1. Field of the Invention
This invention relates to coupling devices, and particularly to a coupling device that provides controlled separability of the coupling device when more than a predetermined amount of force is exerted on the coupling device.
2. Description of the Prior Art
The prior art relating to this invention is believed to reside in the following classes and sub-classes:
______________________________________ Class 114 Sub-classes 210 and 217; Class 280 Sub-class 450; Class 74 Sub-class 2; Class 24 Sub-class 115F; and Class 180 Sub-class 141.5. ______________________________________
A preliminary patentability search conducted through these classes and sub-classes has revealed the existence of the following United States patents:
______________________________________ 1,612,578 2,036,953 2,562,817 2,971,776 3,077,114 3,205,716 ______________________________________
U.S. Pat. No. 1,612,578 relates to a metal draft appliance of the type that might be used to connect a tractor to a trailer or wagon, or a truck to a vehicle being towed. Structurally, the device includes a main cylindrical bore adapted to receive therein a connecting bar provided with two beveled seats at one end. Connecting with the main cylindrical bore are two angularly disposed cylindrical bores within which are contained coil springs having lock pins abutting the beveled seats on the connecting bar. When more than a predetermined amount of force is applied to the connecting bar, the beveled seats impose an axial thrust on the lock pins, which retract, thus compressing the coil springs. Ultimately, the lock pins are retracted sufficiently to permit the connecting bar to pass from the cylindrical bore.
U.S. Pat. No. 2,036,953 teaches a release mechanism used in conjunction with farm equipment, and is adapted to connect an implement control rope to the seat of a tractor in such a way that if the implement becomes detached from the tractor, the control rope will be released instead of broken. The release mechanism comprises a bracket attached to the tractor seat, with a cylindrical member mounted on the bracket. Mounted on the cylindrical member at right angles thereto is a second cylindrical member enclosing a spring and a lock pin that is resiliently biased toward the first cylindrical member. A pin within the first cylindrical member is provided with a circumferential groove into which the lock pin is seated under the impetus of the spring. When more than a predetermined amount of force is exerted on the pin, which is tied to the control rope, the side walls of the groove function as a cam to cause retraction of the lock pin against the force of the spring, ultimately releasing the pin and the control rope.
U.S. Pat. No. 2,562,817 also relates to a farm implement hitch in which the implement is connected to the tractor by a spaced pair of parallel tubular members that telescope into a complementary pair of tubular members mounted on the tractor. Extending transversely between the two sets of telescoped tubular members is a spring pressed detent assembly providing spherical balls at each end that are urged into apertures in the tubular members attached to the implement. When too much drag is imposed by the implement, the balls are cammed into retracted position against spring pressure, thus releasing the telescoped tubular members and permitting separation of the implement from the tractor. A tether connected between the implement and the tractor clutch lever, functions to actuate release the clutch, thus stopping the tractor.
U.S. Pat. No. 2,971,776 also relates to a tractor hitch in which the implement being drawn is released from the tractor upon the application of a predetermined separating force. Structurally, this device includes a tube within which is positioned two annular cam members spaced apart axially and having disposed therebetween in a circular array, two rows of steel balls constituting cam actuators. In the recesses between the steel balls are positioned a series of smaller cam follower balls which impinge on the two rows of steel balls on the one hand and on a reduced diameter section of a connector rod extending axially through the annular cam members and the array of balls. Axial displacement of the connector rod effects a camming action on the small balls, which in turn cam the two rows of larger steel balls apart against the pressure of a spring.
U.S. Pat. No. 3,077,114 relates to a release device which disconnects two lines when more than a predetermined amount of tension is imposed on the lines. In this device, one line is connected to a rod threaded at one end and extending into a cylindrical housing containing a spring surrounding the rod below an abutment plate threaded on the rod. The rod passes through a latch bar pivoted at one end on the housing and at its free end engaging a latch lever also pivoted on the housing. The inner end of the rod is provided with a nut which when pulled against the latch bar disengages the latch bar from the latch lever, which pivots in a manner to release one of the lines.
U.S. Pat. No. 3,205,716 is by the same inventor as the previous patent, and constitutes an improvement of the structure described above in connection with that patent. As in the previous patent, a threaded rod connected to a line is tensioned and upon displacement causes pivotal movement of a latch lever, which is in turn releasably hooked over the end of a release lever. Lateral displacement of the latch lever disengages this lever from the release lever, permitting the tension on the other line to pivot the release lever into a position in which it releases the other line.
From these prior art patents it will be seen that there has been a need for many years for a quick release coupling device that will effect the disconnection of two connected members under specific conditions, usually involving the unexpected imposition of a force tending to separate the connected members. As indicated by the patents listed above, all of the devices of the prior art relate to metallic devices that are heavy and complicated in that they include numerous interrelated parts. Accordingly, it is one of the objects of this invention to provide a quick release coupling that is fabricated totally from plastic.
Another object of the invention is the provision of a quick release device that is particularly applicable for use in connecting a boat to a bouy or anchor.
Still another object of the invention is the provision of a quick release coupling device utilizing only three interconnected parts to effectively connect a boat to an anchor or bouy.
A still further object of the invention is the provision of a quick release coupling device in which decoupling or release upon application of tension beyond a predetermined amount results from elastic deformation of one of the three interconnected parts to effect release of one of the parts.
Yet another object of the invention is the provision of a quick release coupling device which may be adjusted to respond to greater or lesser tension to effect release, and which adjustment may be made without use of tools of any kind.
A still further object of the invention is the provision of a quick release coupling device having an adjustment sleeve that may be manipulated to adjust the amount of tension required to effect release of the coupling, and which incorporates means for locking the adjustment sleeve in its adjusted position.
Still another object of the invention is the provision of a quick release coupling device provided with numerical indicia correlated to positions of an adjustment sleeve and representative of the different force levels at which the coupling device may be set to effect release.
The invention possess other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described since it may be embodied in various forms within the scope of the appended claims.